<!DOCTYPE html>
<html lang="zh" xmlns="http://www.w3.org/1999/xhtml"
>
<head>
    <meta charset="UTF-8">
    <title>404</title>
    <style>
        @import url('https://fonts.googleapis.com/css?family=Montserrat:400,600,700');
        @import url('https://fonts.googleapis.com/css?family=Catamaran:400,800');

        .error-container {
            text-align: center;
            font-size: 180px;
            font-family: 'Catamaran', sans-serif;
            font-weight: 800;
            margin: 20px 15px;
        }

        .error-container > span {
            display: inline-block;
            line-height: 0.7;
            position: relative;
            color: #FFB485;
        }

        .error-container > span {
            display: inline-block;
            position: relative;
            vertical-align: middle;
        }

        .error-container > span:nth-of-type(1) {
            color: #D1F2A5;
            animation: colordancing 4s infinite;
        }

        .error-container > span:nth-of-type(3) {
            color: #F56991;
            animation: colordancing2 4s infinite;
        }

        .error-container > span:nth-of-type(2) {
            width: 120px;
            height: 120px;
            border-radius: 999px;
        }

        .error-container > span:nth-of-type(2):before,
        .error-container > span:nth-of-type(2):after {
            border-radius: 0%;
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: inherit;
            height: inherit;
            border-radius: 999px;
            box-shadow: inset 30px 0 0 rgba(209, 242, 165, 0.4),
            inset 0 30px 0 rgba(239, 250, 180, 0.4),
            inset -30px 0 0 rgba(255, 196, 140, 0.4),
            inset 0 -30px 0 rgba(245, 105, 145, 0.4);
            animation: shadowsdancing 4s infinite;
        }

        .error-container > span:nth-of-type(2):before {
            -webkit-transform: rotate(45deg);
            -moz-transform: rotate(45deg);
            transform: rotate(45deg);
        }

        .screen-reader-text {
            position: absolute;
            top: -9999em;
            left: -9999em;
        }

        @keyframes shadowsdancing {
            0% {
                box-shadow: inset 30px 0 0 rgba(209, 242, 165, 0.4),
                inset 0 30px 0 rgba(239, 250, 180, 0.4),
                inset -30px 0 0 rgba(255, 196, 140, 0.4),
                inset 0 -30px 0 rgba(245, 105, 145, 0.4);
            }
            25% {
                box-shadow: inset 30px 0 0 rgba(245, 105, 145, 0.4),
                inset 0 30px 0 rgba(209, 242, 165, 0.4),
                inset -30px 0 0 rgba(239, 250, 180, 0.4),
                inset 0 -30px 0 rgba(255, 196, 140, 0.4);
            }
            50% {
                box-shadow: inset 30px 0 0 rgba(255, 196, 140, 0.4),
                inset 0 30px 0 rgba(245, 105, 145, 0.4),
                inset -30px 0 0 rgba(209, 242, 165, 0.4),
                inset 0 -30px 0 rgba(239, 250, 180, 0.4);
            }
            75% {
                box-shadow: inset 30px 0 0 rgba(239, 250, 180, 0.4),
                inset 0 30px 0 rgba(255, 196, 140, 0.4),
                inset -30px 0 0 rgba(245, 105, 145, 0.4),
                inset 0 -30px 0 rgba(209, 242, 165, 0.4);
            }
            100% {
                box-shadow: inset 30px 0 0 rgba(209, 242, 165, 0.4),
                inset 0 30px 0 rgba(239, 250, 180, 0.4),
                inset -30px 0 0 rgba(255, 196, 140, 0.4),
                inset 0 -30px 0 rgba(245, 105, 145, 0.4);
            }
        }

        @keyframes colordancing {
            0% {
                color: #D1F2A5;
            }
            25% {
                color: #F56991;
            }
            50% {
                color: #FFC48C;
            }
            75% {
                color: #EFFAB4;
            }
            100% {
                color: #D1F2A5;
            }
        }

        @keyframes colordancing2 {
            0% {
                color: #FFC48C;
            }
            25% {
                color: #EFFAB4;
            }
            50% {
                color: #D1F2A5;
            }
            75% {
                color: #F56991;
            }
            100% {
                color: #FFC48C;
            }
        }

        /* demo stuff */
        * {
            -webkit-box-sizing: border-box;
            -moz-box-sizing: border-box;
            box-sizing: border-box;
        }

        body {
            background-color: #416475;
            margin-bottom: 50px;
        }

        html, button, input, select, textarea {
            font-family: 'Montserrat', Helvetica, sans-serif;
            color: #92a4ad;
        }

        h1 {
            text-align: center;
            margin: 30px 15px;
        }

        .zoom-area {
            max-width: 490px;
            margin: 30px auto 30px;
            font-size: 19px;
            text-align: center;
        }

        .link-container {
            text-align: center;
        }

        a.more-link {
            text-transform: uppercase;
            font-size: 13px;
            background-color: #92a4ad;
            padding: 10px 15px;
            border-radius: 0;
            color: #416475;
            display: inline-block;
            margin-right: 5px;
            margin-bottom: 5px;
            line-height: 1.5;
            text-decoration: none;
            margin-top: 50px;
            letter-spacing: 1px;
        }
    </style>
</head>
<body>
<h1>404 Error Page #3</h1>
<p class="zoom-area"><b>CSS</b> 你似乎发现了别人没发现的页面。 </p>
<section class="error-container">
    <span>4</span>
    <span><span class="screen-reader-text">0</span></span>
    <span>4</span>
</section>
<div class="link-container">
    <a href="javascript:history.go(-1);" class="more-link">返回</a>
</div>
</body>
</html>